Return Pump Advice

McCrary · #1 07/07/2006, 09:21 PM

I am setting up a 110 (48 x 18 x 31) for SPS, but I have no idea how much flow will be necessary. The sump is a 30 gallon and the return pump will be external. The overflows will be able to handle almost any volume ( up to 6000 gph). The question is how much water to pump and how to divide it up when it gets back to the tank. I don't want to blow things around because the water is so strong, but I also don't want to have to buy another pump for a closed loop.

AZDesertRat · #2 07/07/2006, 09:37 PM

You will be better of with a medium flow pump for the return and another high flow pump on a closed loop. High flows through the sump mean high velocities which in turn almost always leads to microbubble problems in the main tank. I would say this is especially true with a smaller sump which both yours and mine are. Even at 1000 GPH and assuming your sump contains 25 of the 30 gallon capacity you will be turning it over every minute and a half . If you had a 6' long 100+ gallon sump it wouldn't be so bad but you will fight bubbles from day one with high velocities in a 30G long like I have. I use a OceanRunner 3500 for a return, the same for a closed loop through a SCWD and Loc Line returns and two Seios which are soon to be replaced by Tunze Nano Streams. I have no problems with sand blowing around and have very few if any dead spots.

staticfishmonger · #3 07/07/2006, 09:39 PM

as far as pumps im partial to external as well and have had good success with sequence pumps. as for how much flow, get as much as you can, you almost cant have to much. what i like to do is have a very high volume of flow with fairly low pressure.

McCrary · #4 07/07/2006, 10:30 PM

AZDesertrat- I have been thinking about the microbubble problem and I was thinking about baffles about 2 inches apart with foam in the first and last one. I have no idea how effective that is going to be if 3200 gph are running through it.

I would be all for a slower return, but space contraints really limit my options. The goal was to return the sump water through 4 Loc-Lines, but I want enough pressure that my SPS will be happy and not so much that my sand and fish are being blown around.

sjm817 · #5 07/07/2006, 11:00 PM

3200 GPH through a 30G sump? That would cause all kinds of problems, massive microbubble problems is just one of them.

PelagicMagic · #6 07/07/2006, 11:02 PM

filter socks will stop all microbubbles

I would go with an external pump to reduce heat. I just installed a reeflo Dart pump and it is very quiet and very powerful. As for the main display I would not rely on the return pump for circulation. Buy some seios or tunze to create flow. If you can spend some $$$ look into vortech propeller pumps

McCrary · #7 07/07/2006, 11:21 PM

PelagicMagic- A filter sock is a good idea.

Would 2400 gph be a more reasonable number to run through the sump? What would be a good amount of flow through the sump? I am try to be ambitious and kill two birds with one stone, but please tell me if I am off my rocker.

sjm817 · #8 07/07/2006, 11:25 PM

30G sump? Maybe 600 GPH max, but I'd keep it to more like 400.

McCrary · #9 07/07/2006, 11:31 PM

sjm817- I would need more flow than that. What would I have to do to put 1600 gph through it?

sjm817 · #10 07/07/2006, 11:32 PM

Quote:

Originally posted by TurboSnail8898
sjm817- I would need more flow than that.

Why?

McCrary · #11 07/07/2006, 11:38 PM

Well, I am comparing the flow for my tank from others I have seen. I look at my skimmer and it pushes out 350 gph and even if I doubled that it would seem to be totally inadequate.

AZDesertRat · #12 07/07/2006, 11:40 PM

For 1600 you would probably need at least a 55G 4' long and then its pushing it. Keep sump flows low to moderate and use a closed loop or Tunzes/Seios. Again you are really asking for trouble with high sump velocities. The in sump solutions suggested all have drawbacks like sponges trapping detritus thus nitrate production and filter socks trapping pods as well as detritus. Both are really temporay fixes or band aids that don't solve the problem only mask it.

McCrary · #13 07/07/2006, 11:42 PM

Would 1200 gph still be too much or is this a more appropriate flow?

McCrary · #14 07/07/2006, 11:45 PM

A closed loop is looking more like the answer. So if I went with a closed loop and a return pump for the sump, what could be used and how many gph will that be? It seems all my previous notions about sumps were pretty far off, lol.

sjm817 · #15 07/07/2006, 11:45 PM

Display flow and sump flow are two different things. Yes, you want strong flow in the display. You don't want it coming from the return pump. A 30G and even the 55G mentioned by AZD are only 12" wide tanks. Assuming you are flowing the "long" way, you will only have 12" wide baffles. Wider baffles help a lot, but you would need a wider sump.

McCrary · #16 07/07/2006, 11:48 PM

sjm817- Would 1200 gph still be too much? Also, would a mag pump work for the return? It would save money and free up space, but noise and heat are concerns.

sjm817 · #17 07/07/2006, 11:53 PM

Yes, 1200 would be too much. 3 - 5x display volume and some say that is too much. That is 330 - 550 GPH for a 110G tank. BTW, if you use a Mag, you need to double the outlet size to get the flow out of it. That is 1.5" plumbing on a Mag9 - 18, and 2" on a Mag 24 - 36.

Many people run undersized plumbing on their Mag pumps and are severely restricting the flow.

AZDesertRat · #18 07/07/2006, 11:55 PM

Thats closer but probably still a little high. You have to figure the sump is a 30G completely full but you will probably have 20 gallons in it as most times and maybe 25 when it is completely topped off maximum. You will be turning the complete volume over once every minute which does not allow much time for microbubbles to dissipate. Overflows and skimmers really aerate the heck out of the water and if its a good skimmer the bubbles are microscopic in size, they jsut don't go away quickly even with multiple baffles.
Put a wooden airstone in an aquarium and run it for a few minutes and then shut it off, turn the room light off and shine a flashlight through the tank side to side and see how long it takes for the bubbles to disappear. None of us are trying to discourage you, we are only pointing out the problems that we have experienced in the past and don't want to see others go through the same things if we can help head it off at the pass. Use a closed loop or other method for movement and use the sump for a refugium and other things like a skimmer, calcium reactor, place for the heater and a phosban reactor.

McCrary · #19 07/07/2006, 11:57 PM

Awesome advice, I am really glad I asked around before ordering all the stuff for the return. How far apart should the baffles be and would you recommend a mag 5 or 7?

sjm817 · #20 07/08/2006, 12:03 AM

Quote:

Originally posted by TurboSnail8898
Awesome advice, I am really glad I asked around before ordering all the stuff for the return. How far apart should the baffles be and would you recommend a mag 5 or 7?

I'd recommend an Eheim 1260! But, if you want a Mag, a Mag7 would be good.
For baffle spacing, the farther the better. I'd go 1.5" minimum.

AZDesertRat · #21 07/08/2006, 12:03 AM

I am not a fan of Mag pumps. They run hot and use more power than comparable pumps like Eheims or Ocean Runners. I use and like the Ocean Runners, I have 3 of them on my 100. An OR 3500 will probably give you around 750-800 GPH at 4 to 5 feet of head. I imagine an Eheim will be about the same.
My baffles are about 1.5 to 2" apart in an over-under-over configuration. Thats far enough apart to get a cleaning brush or Mag Float down between them if I want to clean them.

AZDesertRat · #22 07/08/2006, 12:04 AM

Man, we are thinking alike!

McCrary · #23 07/08/2006, 12:05 AM

So a Eheim 1260 and baffles 2" apart. Thank you

sjm817 · #24 07/08/2006, 12:08 AM

Quote:

Originally posted by AZDesertRat
Man, we are thinking alike!

Scary

McCrary · #25 07/08/2006, 12:17 AM

Whats scary is how helpful you two are.